Hand brace for wheel nuts having an angularly adjustable un-crank arm



Oct. 24, 1967 c. c. ROBINSON 3,348,436

HAND BRACE FOR WHEEL NUTS HAVING AN ANGULARLY ADJUSTABLE U-CRANK ARM Filed June 5, 1965 Mam Chadd BY ML E United States Patent HAND BRACE FOR WHEEL NUTS HAVING AN ANGULARLY ADJUSTABLE U-CRANK ARM Charles Cecil Robinson, Wimborne, England, assignor to Ives (Engineers) Limited, Bournemouth, England Filed June 3, 1965, Ser. No. 461,073 Claims priority, application Great Britain, Oct. 19, 1964, 42,576/64, Patent 1,015,570 8 Claims. (Cl. 81177.9)

This invention relates to hand braces adapted for tightening nuts.

It is common practice to employ a box-type spanner having a brace attachment fitted to it, or integral with it, to provide the leverage means for removing or tightening the wheel nuts of an automobile. Such a tool enables the user to run an untightened nut rapidly up or down its thread, so speeding up the process of replacing or removing a wheel compared say with the use of an ordinary spanner. For the most rapid action the off-set portion of the handle should not be far displaced from the axis of the box spanner, three inches being a convenient distance. However, it is generally found that a greater leverage is necessary than can be provided with the off-set described above for the initial untightening or final tightening of the nut, and the general practice accordingly is to increase the off-set at the expense in the speed of operation.

According to the present invention there is provided a hand brace for tightening or untightening nuts, comprising a box spanner and a brace handle forming therewith a tommy-bar lever, wherein the handle is mounted in the box spanner for rotation about the tommy-bar axis and carries with it in rotation an indexing cam which cooperates with a spring loaded plunger forming the cam follower and mounted in the spanner, there being provided notches or troughs in the cam into which the plunger is urged thereby to locate the spanner in various positions relatively to the handle. The various relative positions can, for example, be the in-line straight-ahead position, the 180 in-line stowing position or one of the 90 positions relative thereto.

With the spanner in the in-line straight-ahead position the brace may be used in the normal manner. The 180 in-line stowing position is provided to facilitate easy and convenient storage. In either of the 90 positions the length of the brace is utilised to provide the additional leverage necessary when untightening or tightening nuts.

Further features of the invention are disclosed in the following description of a specific embodiment and the accompanying drawings, wherein:

FIGURE 1 shows the brace with the spanner in the inline straight-ahead position;

FIGURE 2 shows a sectioned view of FIGURE 1 with the section taken along the axis of rotation and normal to the plane of the paper so as to reveal the indexing mechanism; I

FIGURE 3 shows the brace with the spanner in the 180 in-line stowing position; and

FIGURE 4 shows the brace with the spanner in one of the 90 positions.

Referring to the drawings the handle of the brace is shown at 1. It is usually formed from toughened steel, and probably a stainless steel, with a rounded cross sec- 3,348,436 Patented Oct. 24, 1967.

tion. It comprises a portion 1(c) offset, relative to the proximalend piece 1(b), and a portion at (1a) formed at right-angles to parts 1(b) and 1(c); this latter part 1(a) forms the tommy-bar for the box spanner 2 which is mounted upon it contiguous with an axis extended from the longitudinal axis of part 1(b).

The box spanner 2, also formed of toughened and more probably stainless steel, has a spanner head at its distal end (2a), a shaft 2(b) and a cylindrical boss 2(0) fabricated with a parallel-sided slice of metal removed along the longitudinal axis and a diameter so as to form a forked ending. A hole is drilled through the forked ends, normal to the gap formed by the missing slice, to form a plain bearing for the tommy-bar.

A blind hole 3, drilled or cored coaxially in the proximal end of the spanner, has slidably mounted within it a plunger 4 formed with a pointed or rounded head. A compression spring 5 urges the plunger away from the spanner, the plunger being retained by abutting against an approximately circular cam 6 mounted fixedly on the tommy-bar for rotation within the forked ends of the spanner. The cam is retained in position on the tommybar by means of an Allen (Reg. Trade Mark) grub screw 8 which impinges on or into the tommy-bar in any known manner.

The cam has notches or troughs 7 (a), 7 (b), 7 (c) and 7 (d) formed in its peripheral edge at intervals which notches or troughs are preferably shaped to mate with the shape of the head of the plunger, and the sides of the said notches or troughs form ramps up which the plunger slides as the spanner is turned on the tOmmy-bar.

Preferably the grub screw hole is sited along a radius which passes through the centre of one of the notches or troughs, the grub screw being sufiiciently short not to impinge against the tip of the plunger.

The plunger and cam may be made from any recognised hard wearing material, a preference being had for nylon-type polymer material.

I claim:

1. A hand brace for tightening or untightening nuts comprising a box spanner and a brace handle forming therewith a tommy-bar lever, said handle being mounted in the box spanner for rotation about the tommy-bar axis, a replaceable indexing cam fixed on said tommybar cooperating with a spring loaded plunger housed within the spanner and forming the cam follower, there being provided notches in the cam into which the plunger is urged thereby to locate the spanner in various positions relatively to the handle.

2. A hand brace for tightening or untightening nuts comprising a box spanner and a brace handle forming therewith a tommy-bar lever, said handle being mounted in the box spanner for rotation about the tommy-bar axis, a replaceable indexing cam fixed on said tommy-bar cooperating with a spring loaded plunger housed within the spanner and forming the cam follower, there being provided notches in the cam into which the plunger is urged thereby to locate the spanner relatively to the handle respectively in the in-line straight-ahead position, the in-line stowing position, and in one of the 90 positions relative thereto.

3. A hand brace according to claim 1 wherein the indexing cam is a circular disc formed with said notches in the periphery thereof.

4. A hand brace according to claim 3 wherein the r 3 cam and plunger are fabricated from nylon-type polymer material.

5. A hand brace according to claim 1 wherein the cam and plunger are fabricated from nylon-type polymer material.

6. A hand brace according to claim 2 wherein the indexing cam is a circular disc formed with said notches in the periphery thereof.

7. A hand brace according to claim 6 wherein the cam and plunger are fabricated from nylon-type polymer material.

8. A hand brace according to claim 2 wherein the cam an alp ung r re iabrica ed from ny nyp polymer teri 4 References Cited UNITED STATES PATENTS 1,006,316 10/1911 Turner et a1. 1,835,315 12/1931 McLay 81-1779 2,671,367 3/1954 Modin. 2,943,512 7/ 1960 Nicolaus 74--575 FOREIGN PATENTS 794,100 4/1958 Great Britain. 550,038 12/ 1942 Great Britain.

MILTON S. MEI-IR, Primary Examiner, 

1. A HAND BRACE FOR TIGHTENING OR UNTIGHTENING NUTS COMPRISING A BOX SPANNER AND A BRACE HANDLE FORMING THEREWITH A TOMMY-BAR LEVER, SAID HANDLE BEING MOUNTED IN THE BOX SPANNER FOR ROTATION ABOUT THE TOMMY-BAR AXIS, A REPLACEABLE INDEXING CAM FIXED ON SAID TOMMYBAR COOPERATING WITH A SPRING LOADED PLUNGER HOUSED WITHIN THE SPANNER AND FORMING THE CAM FOLLOWER, THERE BEING PROVIDED NOTCHES IN THE CAM INTO WHICH THE PLUNGER IS URGED THEREBY TO LOCATE THE SPANNER IN VARIOUS POSITIONS RELATIVELY TO THE HANDLE. 